Classic and contemporary models of cognitive dysfunction in schizophrenia include disorders of attention. One of the foremost hypotheses is a generalized inability to maintain or revise attentional "set." Attentional set refers, to the optimal configuration of perceptual, cognitive, and motor systems to more efficiently process specific information relevant to the task at hand. Several popular neuropsychological paradigms have been used to measure attentional set and set shifting deficits in schizophrenia, however, these measure broad cognitive domains and are subject to conflicting interpretations. Despite general consensus that such cognitive deficits are core features of the illness, little is known about specific information processing mechanisms that give rise to the observed deficits in SZ. Using task-switching, EEG paradigms, this research will determine the nature of preparatory and obligatory/stimulus-locked components of attentional processing in SZ. This will lead to the development of improved models of cognitive dysfunction in SZ by testing explicit assumptions about the mechanisms involved; specificity that is lacking in current models of set shifting deficits. Additionally, by formalizing existing and new hypotheses regarding cognitive dysfunction in SZ with computational models this research will greatly improve the specificity of the measures currently used and will promote a deeper understanding of the mechanisms that give rise to the phenomenology of schizophrenia.